Surface treating apparatus and method



June l, 1965 l.. l.. DUNCAN r-:TAL 3,186,132

SURFACE TREATING APPARATUS AND METHOD Filed sept. 16, 196s 2 sheets-sheet 1 INV ENTORS LEON L. DUNCAN DONALD 1 TEMPLE TToRNEYs June l, 1965 L. L. DUNCAN ETAL SURFACE TREATING APPARATUS AND METHOD Filed Sept. 16, 1965 2 Sheets-Sheet 2 INVENTOR` LEON L. DUNCAN DONALD L. TEMPLE WML/.4%

ORNEYS United States Patent() 3,186,132 SURFACE TREATHNG APPARATUS AND METHGD Leon L. Duncan and Donald L. Temple, Wasgton, Mo.,

assignors to Zero Manufacturing Company, Washington, Mo., a company of Missouri Filed Sept. 16, 1963, Ser. No. 363,985 12 Claims. (fill. S1-11) This invention relates to a surface treating apparatus and more particularly .to a cleaning and peening apparatus that has a portable operating head in the form of a gun. The invention also relates to an improved method of blasting and peening a surface with finely divided material and effectively removing the material and waste debris from the working area without contaminating the atmosphere.

The apparatus of the present invention is adapted to be used as a mobile and portable implement for cleaningT and blasting surfaces when it is desired to clean surfaces in place and avoid scattering the treating and dust particles throughout the atmosphere.

In operation, this invention will insure that the treating material and Waste dust are totally coniined to the local area being treated. VAlso means are provided to scavenge thoroughly these materials from the working area to a separator for substantially total recovery of the treating material.

In addition to the above advantages, the instant invention provides a very effective method and apparatus for impelling treating material and peening a working surface. This latter object is accomplished by providing a par-tial vacuum head immediately above the working surface and directing several currents of air from points above the head to create a maximum of turbulence.

The above and other objects will appear from the drawings and following description.

FIGURE 1 is a side elevation in partial section showing the apparatus in operation with air and treating material passageways in one arrangement connected to the channels in a hollow housing.

lFIGUR-E 2 is a side elevation in par-tial section illustrating a modified arrangement in a second apparatus.

AFIGURE 3 is a side elevation in partial section illustrating still another arrangement in a third apparatus.

FIGUR-E 4 is a side elevation in par-tial section of a further embodiment of the invention.

Referring to the device illustrated in FIGURE l, the apparatus 1 comprises a hollow housing having a iluid, air, connection pipe 2 threadably engaged with gun unit 5 and fixed by a nut 3 abutting the iiange 4 of the unit. Unit 5 is provided with eyelet 6 and a hollow handle portion 7 for manipulative purposes. Fitting 8 is threaded into the handle por-tion of unit 5 to provide a conduit for admitting `treating material 23 into the channel of the housing. Locking nut 9 serves to x a line threaded to the fitting for connection to a supply source of treating material (not shown).

The lower end 1@ of unit 5 is threadably received in collar 11 of member 12 above exhaust outlet 13, Outlet I13 leads laterally away from the hollow center to either a waste disposal or separator system (not shown). Collar 14 is connected at its upper periphery to member 12 and the bottom of the collar is fastened to and supports circular skirt 1S ofyieldable material. The connections .of collar 14 with member 12 and skirt 15' should be airtight! to form an airtight chamber at the bottom of mem# ber 12. Located below the exhaust outlet but above skirt 15 is a second air inlet 19 which leads'to pressurized air line 16 having regulator gage 17 and into the lower portion of member 12 in the vicinity of surface 18 through manifold 2G and orifices 21 in the skirt 15.

In operation, air under pressure is forced in the top ICC of the housing and channeled down through the center of unit 5 whereupon the passage of the stream of air 22 draws the iinely divided peening beads 0r other treating material 23 in its wake. The treating material can be metered to the conduit of handle 7 from a hopper having a restricted outlet (not shown) that is connected to fitting 8. A suction pump (not shown) is connected to exhaust outlet 13 with a hose to provide reduced pressure at the bottom of the housing and to create a partial vaccum head of say .5-3 pounds per square inch less than atmospheric pressure in the space immediately above the working surface 18. The operator rst places skirt 15 in close contact with the working surface 18 so that an airtight chamber is formed at the bottom of the housing. The skirt 15 is fashioned from material that is deformable so that it can closely conform to irregular surfaces. The air stream and treating material are then impinged on the working surface and considerably more turbulence is created by directing additional air from air line 16 at the working surface. The expended air, treating material and waste are scavenged out of the exhaust outlet to a separator or disposal system. lt is important to the present invention that suicient suction be maintained to create a partial vacuum head at the bottom of the housing in the general area defined by the sides of the skirt and the working surface. lt will be appreciated that because a minimum velocity 2600 feet per minute is required to move a particle with no velocity of its own, iine particles are not stopped suiiiciently by skirts merely consisting of brushes to reverse the flow of the particle.

FIGURE 2 shows a modification of the device in which the apparatus as a whole is indicated at 101. The gun unit 5 and its connections are the same as shown in FIGURE l. Threaded end 10 of the unit is also threaded in a collar 1.11 of member 112 and an exhaust outlet 113 is connected to a suction pump. However, a flaring tube means 114 extends down from collar 111 to deiine an annular -space 115 within the vacuum chamber of member 112. Also an air restrictor tube 117 is connected to inlet 119 at the upper part of member 112. Skirt 116 is attached to the lower portion of member 112 with a substantially airtight joint and provides a vacuum chamber at the bottom of member 112 above the interface of the apparatus and the working surface. A plurality of conduits 12() convey air from inlet 119 through skirt 116 into the vicinityV of surface 118.

In practice, the operator rmly abuts skirt 116 of the apparatus against the surface to be Worked and then directs a stream of compressed air 22 through the channel of the housing so that the peening material 23 is entrained and directed towards surface 118. The pressurized air and impelled materialpeens the working surface 118 and is rapidly sucked out of outlet 113. The air passing through the restrictor tube 117 is regulated by adjusting inlet 119 so that the proper amount of additional airis directed to the working surface through orifices 12d and a maximum turbulence created. Also, as in the previous embodiment, a partial'vacuum head is formed and maintained at the zone defined by the skirt 116 and surface 11S.

FIGURE 3 shows still another modification of the device inwhich 201 indicates the apparatus as a Whole. The gun unit 5 and its connections are the same as shown in FlGURES l and 2. Threaded unit 210 is tightly screwed in collar 211' of member 212. Exhaust outlet 213 extends laterally from channeled center of the housing and is designed to be connected to a line from a vacuum pump. A

A collar 214 is joined at its lower periphery to the lower extremity of member 212. A skirt 215 of yieldable material is also joined to the lower part of the collar and its outer dimensions roughly conform to those of collar 214 as shown in FIGURE 3. A circular space 219, open to the atmosphere at 216, is formed between the collar and the terminal portion of member 212. The connection between collar 214 and member 212 as well as the joint between the collar and skirt 215 are sealed airtight so that the bottom of the housing forms a substantially airtight chamber when working surface 21S is engaged with skirt 215. A series of perforations 217 around the sides of member 212 lead air from space 219 into the channel of the housing above the skirt.

In operation, a high velocity stream of air 22 and entrained treating material 23 are directed at the working surface 218 confined by skirt 215. Suction is applied to outlet 213 so that as in the previous embodiments a partial vacuum head is formed in the area immediately above the working surface 218 within the skirt. Outside air is drawn through the opening 216 and perforations 217 and directed to the working surface 218 to create extreme turbulence. The treating material and waste debris are exhausted to a disposal or separator system to recover the treating material for reuse.

FIGURE 4 shows a further embodiment of the device in which 391 indicates the apparatus as a whole. The gun unit 5 and its connections are the same as shown in the previously described figures. Threaded unit is tightly screwed in collar 311 of member 312. The exhaust outlet 313 extends normally from member 312 and is adapted for connection to a line from a vacuum pump. It will be noted in the embodiment that the member 312 has the shape of a truncated cone and surrounds a funnel-shaped delivery conduit 314 which extends down from the collar 311 to dene an annular space 316 within the vacuum chamber of member 312. In member 312, opposite the exhaust outlet 313, is an air inlet 319. The lower portion of member 312 has a ring part 321 which includes an annular groove 320 with a skirt member 315 made of a conformable material fitted firmly therein so that the bottom of the housing forms a substantially airtight chamber when the working surface 318 is engaged with skirt 315.

In operation, a high velocity stream of air 22 and entrained treating material 23 are directed at the Working surface 318 confined by the skirt 315. Suction is applied to the outlet 313 so that a slight sub-atmospheric head is formed in the area immediately above the working surface 318 within the skirt 315. Outside air drawn through the opening 319 creates considerable turbulence in primarily the annular space 316 and secondarily in the space immediately above the working surface within the skirt 315. Additional turbulence in such space is also created by the blasting operation itself. The treating material and waste debris are exhausted to a disposal separator system to recover the treating material for reuse.

From the foregoing it will be appreciated that applicant has designed a portable apparatus that is capable is cleaning or blasting surfaces without scattering debris and contaminating the atmosphere. It will also be appreciated that a high or substantially total recovery of the treating material can be realized with the apparatus described above. By creating a partial vacuum head above the working surface and directing air at the surface from several sources above the vacuum head, extreme turbulence is created and an effective method of surface treatment is provided. A.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, for modifications will be obvious to those skilled in the art.

We claim:

1. A surface' treating apparatus comprising a hollow housing, means for admitting a stream of air under pressure at the top of said housing, airtight means for engaging a working surface to form an airtight chamber at the bottom of said housing, a plurality of passageways leading into the sideof said housing, said passageways including conduit means for admitting treating material within said housing to said stream of air, an exhaust outlet positioned below said conduit means and air inlet means located in said chamber above said working surface.

2. A surface treating apparatus comprising a hollow housing, means for admitting a stream of air under pressure at the top of said housing, airtight means for engaging a working surface to form an airtight chamber at the bottom of said housing, a plurality of passageways leading into said housing, said passageways including conduit means for admitting treating material within said housing to said stream of air, an exhaust outlet positioned below said conduit means and air inlet means located in said chamber between said outlet and said working surface.

3. A surface treating apparatus comprising a hollow housing, means for admitting a stream of air under pressure at the top of said housing, means for engaging a working surface to form a substantially airtight chamber at the bottom of said housing, a plurality of passageways leading into said housing, said passageways including conduit means for admitting treating material within said housing to said stream of air, an exhaust outlet positioned below said conduit means, air inlet means for admitting a second stream of air under pressure, said inlet means being located in said chamber between said outlet and said working surface.

4. A surface treating apparatus comprising a hollow housing, means for admitting a stream of air under pressure at the top of said housing, means for engaging a working surface to form a substantially airtight chamber at the bottom of said housing, a plurality of passageways lea-ding into the side of said housing, said passageways including conduit means for admitting treating material within said housing to said stream of air, an exhaust outlet positioned below said conduit means, air inlet means located in said chamber between said outlet and said working surface, said inlet means being .a series of perforations.

5. A surface treating apparatus comprising a hollow housing, means for admitting a stream of air under pressure at the top of said housing, means for engaging a working surface to form a substantially airtight chamber at the bottom of said housing, a plurality of passageways leading into the side of said housing, said passageways including conduit means for admitting treating material within said housing to said stream of air, tube means extending towards the working surface for directing said stream of air and material at said surface, said tube means dening an annular space within said chamber, an exhaust outlet and air inlet means located on substantially opposite sides of said chamber, said inlet means leading into the upper portion of said annular space above said working surface.

l 6. The invention of claim 5 wherein the air inlet means is an air restrictor tube.

7. 'A surface treating apparatus comprising a hollow housing, means directing a stream of high velocity fluid through said housing to the surface being treated, entraining means entraining treating material in said stream, an airtight deformable surface contacting head included 1n said housing, forming an airtight chamber at the bottom of said housing, suction means communicating with said head removing treating material and fluid from the vicinity of the surface being treated, and fluid ingress means introducing uid in the vicinity of the periphery of said contacting head.

8. A surface treating apparatus comprising a hollow housing, means directing a stream of high velocity uid through said housing to the surface being treated, entraining means entraining treating material into said stream, an airtight deformable surface contacting head included in said housing, forming an airtight chamber at the bottom of said housing, suction means communieating with said head and removing treating material and Huid from the vicinity of the surface being treated, and uid ingress means introducing fluid into said housing causing thereby turbulence in said treating material and fluid being removed from said head.

9. A method of blasting and peening a surface comprising directing a stream of airV under pressure at the surface to be treated, introducing treating material in the air stream and impinging the material ron the surface, directing additional air at the surface to cause turbulence, creating a partial vacuum head in the space immediately above the surface being treated by conning the area within .an airtight chamber and withdrawing the expended air and material through an exhaust outlet under reduced pressure, the expended air and material being withdrawn at a point above the vacuum head.

10. The method of claim 9 wherein the said additional air is supplied under pressure.

1l. A method of blasting and peening a surface comprising directing a stream of air under pressure at the surface to be treated, introducing treating material into 20 the air Stream and impinging the material on the surface,

directing additional air at the surface to cause turbulence, creating a partial vacuum head in the space immediately above the surface being treated by conning the area Within an airtight chamber and withdrawing the expended air and material through an exhaust outlet under reduced pressure, the expended air and material being withdrawn at a point above the vacuum head and the source of ladditional air.

12. The method of claim 11 wherein the additional air is supplied under pressure.

References Cited by the Examiner UNITED STATES PATENTS 787,389 4/05 Moorhead 15--345 2,270,5 79 1/ 42 Chamberlin et al.

FOREIGN PATENTS 764,171 12/56 Great Britain. 786,180 11/ 5 7 Great Britain.

I. SPENCER OVERHOLSER, Primary Examiner. 

1. A SURFACE TREATING APPARATUS COMPRISING A HOLLOW HOUSING, MEANS FOR ADMITTING A STREAM OF AIR UNDER PRESSURE AT THE TOP OF SAID HOUSING, AIRTIGHT MEANS FOR ENGAGING A WORKING SURFACE TO FORM AN AIRTIGHT CHAMBER, AT THE BOTTOM OF SAID HOUSING, A PLURALITY OF PASSAGEWAYS LEADING INTO THE SIDE OF SAID HOUSING, SAID PASSAGEWAYS INCLUDING CONDUIT MEANS FOR ADMITTING TREATING MATERIAL WITHIN SAID HOUSING TO SAID STREAM OF AIR, AN EXHAUST OUTLET POSITIONED BELOW SAID CONDUIT MEANS AND AIR INLET MEANS LOCATED IN SAID CHAMBER ABOVE SAID WORKING SURFACE.
 9. A METHOD OF BLASTING AND PEENING A SURFACE COMPRISING DIRECTING A STREAM OF AIR UNDER PRESSURE AT THE SURFACE TO BE TREATED, INTRODUCING TREATING MATERIAL IN THE AIR STREAM AND IMPINGING THE MATERIAL ON THE SURFACE, DIRECTING ADDITIONAL AIR AT THE SURFACE TO CAUSE TURBULENCE, CREATING A PARTIAL VACUUM HEAD IN THE SPACE IMMEDIATELY ABOVE THE SURFACE BEING TREATED BY CONFINING THE AREA WITHIN AN AIRTIGHT CHAMBER AND WITHDRAWING THE EXPENDED AIR AND MATERIAL THROUGH AN EXHAUST OUTLET UNDER REDUCED PRESSURE, THE EXPENDED AIR AND MATERIAL BEING WITHDRAWN AT A POINT ABOVE THE VACUUM HEAD. 